Gem Tang

Aquarium Requirements

Minimum Tank Size: 125 gallons (475 litres) or larger

Temperature: 24–27°C (75–81°F)

pH: 8.1–8.4

Specific Gravity: 1.020–1.025

Alkalinity: 8–12 dKH

Ammonia & Nitrite: 0 ppm

Nitrate:< 10 ppm

Aquascape: Open rockwork with ample swimming space and grazing surfaces

The Gem Tang requires a spacious aquarium with excellent water quality, strong circulation, and high oxygenation. A mature system with established rockwork and natural algae growth is ideal. Stability is key, as this species can be sensitive to rapid changes in water parameters. Regular maintenance, efficient filtration, and consistent water changes are essential for long-term success.

Diet and Feeding

The Gem Tang is primarily herbivorous and benefits from frequent feedings to support its active lifestyle and immune health. In the wild, it spends much of the day grazing on algae. In captivity, offer a varied and nutrient-rich diet including:

• Dried seaweed (nori) or macroalgae

• Spirulina-based flakes or pellets

• High-quality herbivore formulations

• Occasional frozen foods such as mysis shrimp for dietary variety

Feed two to three times daily in small portions. Continuous access to algae sheets or grazing stations is highly recommended.

Temperament and Compatibility

Gem Tangs are generally peaceful but can be territorial toward other tangs, particularly those of similar body shape or genus (Zebrasoma). In large systems, they may coexist with other tangs if introduced carefully, ideally at the same time or with adequate space.

They are best housed with peaceful to semi-aggressive reef fish that can tolerate active swimmers. Avoid overly aggressive tankmates that may cause stress or competition for food.

Reef Compatibility

The Gem Tang is reef safe and will not damage corals or most invertebrates. Its natural grazing behaviour makes it beneficial in reef aquariums by helping control nuisance algae. Adequate swimming space is essential to prevent stress and ensure natural behaviour.

Additional Information

Maximum Size: Approximately 22 cm (9 inches)

Lifespan: 10+ years with proper care

Difficulty Level: Advanced

Natural Behaviour: Active swimmer, constant grazer, semi-territorial

The Gem Tang is a rare and exceptional species that rewards experienced aquarists with unmatched beauty and presence. When housed in a large, stable, and mature aquarium with excellent water quality and a varied herbivorous diet, it can become a breathtaking centrepiece and long-term resident of a premium reef system.